1. Field of the Invention
The present invention relates to means for indicating the blown or unblown condition of an electric fuse. More specifically it relates to a manner of easily mounting such an indicator on a lateral wall of a fuse.
2. Description of the Prior Art
Electric fuses are generally provided with blown fuse indicators in the form of a spring-biased indicating pin. Such pins are normally held in position by a restraining wire, and are allowed to move to a blown fuse indicating position in response to blowing of the fuse and subsequent melting of the restraining wire. Generally blown fuse indicating pins are arranged at one of the end surfaces of the fuse. Since the space available at this location is relatively limited, the pins are generally of small size. This fact combined with the fact that the end surfaces of fuses are generally much less exposed to view than the lateral surfaces thereof, imposes serious limitations on the usefulness of blown fuse indicators of the aforementioned conventional type.
In an effort to achieve a more conspicuous indication of whether or not a fuse has blown, blown fuse indicators have been arranged at the lateral surfaces of fuses, or their casings, respectively. This arrangement greatly facilitates the supervision and maintenance of fuse-protected electric distribution systems, but requires the provision of a perforation or hole in the lateral wall of the casing of such fuses, which impairs the mechanical integrity of the casing.
U.S. Pat. No. 4,023,133, BLOWN FUSE INDICATOR to E. J. Knapp, Jr. assigned to the same assignee as the present invention discloses an arrangement which provides a highly visible blown fuse indicating means on the lateral surface of a fuse casing, without any impairment of the mechanical integrity of the casing.
The above described indicator makes use of a conventional end mounted indicator and provides a side mounted assembly which comprises a plurality of additional parts to transfer the action of the end mounted indicator to a second indicator positioned at right angles with respect to the end mounted indicator.
It is a primary object of this invention to provide a side mounted blown fuse indicator which maintains the structural integrity of the fuse casing while requiring a minimum number of parts.
It is another object of this invention to provide a side mounted blown fuse indicator which has no components extending beyond the ends of the fuse.